Vehicle security device

ABSTRACT

A vehicle security arrangement includes at least one functional control unit, which provides a first code word; a theft protection control unit, which is coupled via a bus to the at least one functional control unit; and at least one input unit, which transmits to the theft protection control unit a second code word which the theft protection control unit forwards to the at least one function control unit. The theft protection control unit may initiate the provision of the first code word and the second code word. In the at least one functional control unit, a comparison of the first code word of the at least one functional control unit with the second code word takes place. In case of agreement between the first code word and the second code word, the at least one functional control unit enables itself.

FIELD OF THE INVENTION

The present invention generally relates to security systems, and moreparticularly to a vehicle security arrangement.

BACKGROUND INFORMATION

From, German Patent No. 43 25 657 describing a theft preventionmechanism for vehicles brought about by specifically blocking assembliescritical to operation. Action modules handle the disabling or enablingof the respectively assigned modules. A code stored on a code key isdetected by a code reader and forwarded to all action modules. A logicunit of the action module compares the code with information stored inthe code memory of the action module. If both do not agree, the actionmodule deactivates the associated functional assembly. It is alsoprovided that in case of a mismatch, the action module can bring aboutthe destruction of the relevant assembly. Data transmission and datacomparison in the action modules are triggered by introducing the codekey into the code reader.

SUMMARY OF THE INVENTION

The present invention provides a vehicle security arrangement thatrealizes increased theft protection.

According to the present invention, improved theft protection isachieved in that the enabling of each functional control unit takesplace as a function of a comparison of two code words. The first codeword is provided by the respective functional control unit and thesecond code word is provided by an input unit. The theft protectioncontrol unit initiates the provision of both code words. Byincorporating multiple functional control units relevant to traveloperation, the security against unauthorized start-up of the vehicle isfurther increased. Each functional control unit checks for itselfwhether an authorized user is accessing the vehicle. This renders itmore difficult, in particular, to exchange functional control units withunits coming, e.g., from stolen vehicles, since the functional controlunits must be matched to the theft protection control unit and also tothe input unit. If this is not the case, then the functional controlunit denies its usage. The control of the enabling procedure by thetheft protection control unit increases the security against monitoringby influencing code words in a randomly controlled manner. The theftprotection control unit affects a precise preselection which gets theauthorization of the possibly multiple input units to provide the secondcode word.

The present invention further provides that a forwarding of the secondcode word, which is provided by the input unit, to the functionalcontrol unit takes place if the second code word matches the code wordexpected by the theft protection control unit. A further authorizationquery performed in the theft protection control unit increases the theftprotection. The measure also increases the convenience, for instance, ifdue to transmission error(s) the second code word arrives garbled at thetheft protection control unit. This can trigger a request to the inputunit to repeat the transmission or provision procedure of the secondcode word without the incorrect second code word already having led to amalfunction of the functional control units.

The present invention may also provide an authorization algorithm orkeyword or both assisting in the generation of the first and the secondcode words. Particularly with a vehicle-specific keyword, theauthorization algorithm can be chosen the same for each vehicle. Thisseparation ensures on the one hand that an individual code word isassigned to each vehicle. On the other hand, it is guaranteed for themanufacturer that by using one and the same authorization algorithm foreach vehicle, a high degree of standardization is achieved, whichbecomes noticeable in terms of decreased costs in the manufacturingprocess.

The present invention may also provide that to generate the first andsecond code words, a third code word is used whose provision takes placethrough the theft protection control unit. Protection against monitoringcan be realized in this manner by drawing upon, for example, anotherthird code word, randomly controlled, for each initiation procedure.Constant communication procedures are thus avoided, thereby decreasingthe risk of transferring the vehicle through intentional manipulationinto a driveable state.

The present invention may also provide that the initiation of the theftprotection control unit occurs after actuating a switch. The coupling ofthe enabling process, e.g., with an ignition lock, increases thesecurity by also taking into account conventional locking devices.

The present invention may also provide, for example, transponders and/orelectronic chip cards input units. The transponder increases theconvenience through wireless communication with the theft protectioncontrol unit. The electronic chip card is advantageous in that themechanical accessibility of the read unit can be made more difficultthrough additional control mechanisms, which further enhances security.

The present invention may also provide a master input unit containingthe keyword. This master input unit is required if functional controlunits or input units are to be exchanged. The exchange ofvehicle-specific modules in stolen vehicles is made considerably moredifficult in this manner.

The present invention may also provide a technique for parametrizing avehicle security arrangement, the functional control unit and theftprotection control unit being operated in a parametrizing mode. Anadditional device informs the functional control unit and the theftprotection control unit of the vehicle-specific keyword which is thenforwarded on the part of the theft protection control unit to the inputdevice. This procedure enables a favorable parametrizing process from amanufacturing-engineering viewpoint at the end of the assembly line.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a block diagram of one embodiment of a vehiclesecurity arrangement.

FIG. 2 shows a flowchart illustrating the operation of one embodiment ofthe vehicle security arrangement.

FIG. 3 shows a flowchart illustrating an initial start-up process forone embodiment of the vehicle security arrangement.

FIG. 4 shows a flowchart illustrating how to parametrize new input unitsand new functional control units for one embodiment of the vehiclesecurity arrangement.

DETAILED DESCRIPTION

FIG. 1, illustrates a theft protection control unit DS in interactionwith at least one functional control unit F_(i) via a bus. The theftprotection control unit DS communicates with an input unit E. Thefunctional control unit F_(i) provides a first code word C_(i), theinput unit E a second code word C, the theft protection control unit DSa third code word C_(D).

Each of the functional control units F_(i) —here, the index stands forthe ith functional control unit F_(i) —generates in each case for itselfthe first code word C_(i). In a vehicle, depending on the outfitting,different functional control units F_(i) are present, e.g., controlunits for engine control, automatic transmission control, anti-locksystems, anti-slip control, starting of control, power steering,ignition control, central interlocking or level control. All arerequired for smooth operation of the vehicle. Each functional controlunit F_(i) generates the first code word C_(i) for itself andindependent of the others. The algorithms and data required are storedin each individual functional control unit F_(i). The data exchangeamong the functional control units F_(i) as well as with the theftprotection control unit DS takes place via the bus.

The input unit E is enabled, e.g., through an algorithm, to provide thesecond code word C as a function of a keyword. A transponder is used asinput unit E. The transponder contains transmitters as well as receiversfor electromagnetic waves and can assume, for example, the form of anelectronic chip card, formed as a key trailer or integrated in thevehicle key. Multiple input units E formed as transponders enable usageof the same vehicle by multiple persons. Besides wireless communication,an electronic chip card can also be used as input unit E. Assigned tothe card is a card read/write station into which the card must beintroduced. The data transmission between the input unit E and the theftprotection control unit DS can be realized in any appropriate mannere.g., infrared communications.

The theft protection control unit DS handles the data exchange with theinput unit E.

Referring to FIG. 2, the functioning of the arrangement illustrated inFIG. 1 is described hereafter. The start of the driving authorizationprocedure is triggered by step 100, Switch ON. The switch is actuated,e.g., via an ignition key. In this manner, the theft protection controlunit DS recognizes that it is desired to start the vehicle.

It then prepares the initiation, step 101. The data exchange of thetheft protection control unit DS with input units E and functionalcontrol units F_(i) takes place according to a “challenge/response”process. The theft protection control unit DS generates a challenge. Thechallenge can contain a command and/or the third code word C_(D). Thecommand triggers in the respective receiver—functional control unitF_(i) and input unit E according to one embodiment of the presentinvention a data processing procedure in which the first and second codeword C_(i), C are generated. If the third code word C_(D) is transmittedas additional information of the challenge along with the command, arandom generator integrated in the theft protection control unit DS canre-provide for reasons of monitoring security the third code word C_(D)for each authorization check. Similarly the step 101 may includeselecting a special input unit E to which the challenge is to betransmitted. In this manner, certain input units E can be intentionallydisabled in case they were lost. The present invention also contemplatesaddressing in a preferred manner the one input unit E with which thevehicle was last used.

In a step 102, the theft protection control unit DS transmits thechallenge provided in step 101. It contains the command “Provide codeword” and possibly, the third code word C_(D). All functional controlunits F_(i) connected to the bus and the input units E selected on thepart of the theft protection control unit DS receive this challenge.Input unit E as well as functional control units F_(i) provide theircode words C, C_(i) after they have received the command of the theftprotection control unit DS in step 103 and 106 respectively. In step104, the respective input unit E begins to generate the second code wordC. Here, an authorization algorithm stored in the input unit E isinitiated which computes the second code word C as a function of, forexample, a vehicle-specific keyword and/or the third code word C_(D).

The connected functional control units F_(i) proceed likewiseindependently of one another. In a step 107, each functional controlunit F_(i) provides for itself the first code word C_(i) as a functionof an authorization algorithm. The algorithm is stored separately ineach functional control unit F_(i). It computes the corresponding firstcode word C_(i) as a function of, for example, the vehicle-specifickeyword and/or of the third code word C_(D.)

It should be noted that the general principle for generating the codeword C_(i), C must agree in the functional control units F_(i) among oneanother and is identical to the input unit E. The authorizationalgorithm and the data which it accesses must agree in functionalcontrol unit F_(i) and input unit E to be able to bring the vehicle intooperation. If the authorization algorithm of the functional control unitF_(i) accesses the keyword, then the authorization algorithm of theinput unit must also proceed in the same manner. If the authorizationalgorithm of the functional control unit F_(i) requires the third codeword C_(D), then the authorization algorithm of the input unit E mustalso fall back upon it. Therefore, if the authorization algorithm, therespectively used keyword and possibly the third code word agree for thefunctional control unit F_(i) and the input unit E, then the first andsecond code word, C_(i), C are identical.

The input unit E generates and provides the second code word C in step104. In a step 105 the input unit E transmits the second code word C tothe theft protection control unit DS. The latter receives the secondcode word C and possibly evaluates it in step 109. For evaluation, forexample, a control code word may be computed as a function of theauthorization algorithm the keyword, or both which are stored in thetheft protection control unit DS. If the authorization algorithm of step104 also uses the third code word C_(D), then it must also be taken intoaccount accordingly in step 109. Subsequently, a comparison of thesecond code word C with the control code word takes place. In step 110,the query takes place whether the second code word C is okay. If this isnot the case, i.e., the second code word C and the control code word aredifferent, then an error case is present, step 111. It is imaginable torepeat the steps 102 to 110 again in order to avoid transmission errorsbetween the input unit E and the theft protection control unit DS.However, the error case could also lead immediately to the furtherprevention of the enabling of the functional control units F_(i). If,according to the query, step 110, the second code word C is okay, then astep 112 follows. Here, the theft protection control unit DS transmitsthe second code word via the bus to all functional control units F_(i).The second code word C is forwarded here unprocessed directly as theresult determined by the input unit E.

During the previously described steps, the functional control unitsF_(i) wait in a step 108 for the second code word C. All functionalcontrol units F_(i) receive the second code word C and evaluate it in,step 113. Each functional control unit F_(i) performs in a query 114 acomparison of the second code word C with the first code word C_(i)provided respectively in step 107. The two code words C, C_(i) thenagree if, respectively, authorization algorithm, keyword and possiblythe third code word C_(D), stored once in the input unit E, once in thefunctional control unit F_(i), are identical. If the first and secondcode words C_(i), C do not agree, then the error case applies, step 115.In the error case, the corresponding functional control unit F_(i) doesnot enable itself and thus blocks the starting process. If the first andsecond code words C_(i), C agree, then the relevant functional controlunit F_(i) enables itself in, step 116. As already explained, each ofthe functional control units F_(i) executes the steps 106 to 108 and 113to 116 as a function of the respective authorization algorithm andkeyword which are stored in the respective functional control unitsF_(i). The error case in step 115, can thus also occur if, for example,when exchanging a functional control unit F_(i) either the authorizationalgorithm does not agree with the one stored in the input unit or if thevehicle-specific keywords of the input unit E and the functional controlunit F_(i) deviate from one another. Thus, the unauthorized exchange ofa functional control unit F_(i) also blocks the start process.

Referring to FIG. 3, one embodiment for start-up of the vehicle securityarrangement according to the present invention is described. Thesubsequently described process steps can be carried out, for example, atthe end of the assembly line after installation of the functionalcontrol units F_(i) in the motor vehicle. According to step 201, thetheft protection control unit DS and the functional control units F_(i)are operated in a parametrization mode. Here, it is contemplated thatthe authorization algorithm is already implemented in each case in afixed manner in the theft protection control unit DS and in thefunctional control units F_(i). For successful execution of theauthorization procedure, the vehicle-specific keyword is necessary. In anext step 202, an additional device is connected. For example, via aprovided diagnostics interface, the additional device can communicatevia the bus both with the theft protection control unit DS as well aswith the functional control units F_(i). With the aid of the additionaldevice, the training procedure can be started, for example by operatingpersonnel in, step 203. Subsequently, in a step 204, the keyword istransmitted to the theft protection control unit DS and to thefunctional control units F_(i). These transmission processes maypossibly be verified through suitable control procedures. Subsequently,the theft protection control unit DS transmits the keyword to the inputunit E in, step 205. Particularly with regard to later maintenance work,it may be advantageous to assign different authorization functions tothe input units E. It can thus be provided that the parametrization ofan exchanged functional control unit F_(i) can take place only inconjunction with a master input unit. Also, the training of new inputunits E can be performed properly only in conjunction with the masterinput unit. After step 205, in a step 206 an input unit E is selectedwhich as the master input unit is assigned a special authorization.

In the flowchart illustrated in FIG. 4, one embodiment according to thepresent invention described for how to parametrize new input units E andnew functional control units F_(i) following the initial start-up. In astep 301, an additional device is connected, e.g., to a diagnosticsinterface. Then, in step 302 the master input unit is checked, e.g.,through the challenge-response process as described above. If the masterinput unit is not okay, query 303, the process is interrupted as theerror case in, step 304. If the master input unit is okay, then theauthorization exists in a step 305 to install a new functional controlunit F_(i) in the motor vehicle or to train a new input unit E. If thenew input unit E or the new functional control unit F_(i) are capable ofexchanging data, then the keyword is transmitted to them in a step 306.The keyword is stored by, the new input unit E or by the new functionalcontrol unit F_(i) in step 307. This training process is checked in aquery 308, “Verification okay?”. This verification may include, forexample, the theft protection control unit DS, according to thechallenge-response process already described, demanding a first orsecond code word C_(i), C from the new functional control unit F_(i) orfrom the new input unit E which is compared with the control code wordcomputed in the theft protection control unit DS. If the verification isnot okay, then the training procedure can be interrupted or possiblyrepeated in, step 309. If the verification is okay, then the newfunctional control units F_(i) and new input units E are integrated in,step 310. The present invention to the new input unit E in the theftprotection control unit DS a specific receiver code in order to be ableto selectively control the new input unit E. These data could possiblyalso be communicated to the master input unit.

What is claimed is:
 1. A vehicle security arrangement for a vehicle,comprising: a theft protection control unit; at least one functionalcontrol unit, wherein the at least one functional control unit iscoupled to the theft protection control unit via a bus and generates,during normal operation of the vehicle, a first code word in response toa request by the theft protection control unit; and at least one inputunit, wherein the at least one input unit, in response to a request fromthe theft protection control unit, generates and transmits a second codeword to the theft protection control unit, and wherein the theftprotection control unit forwards the second code word to the at leastone functional control unit via the bus, wherein the at least onefunctional control unit compares the first code word with the secondcode word and, in the case of an agreement, the at least one functionalcontrol unit enables itself.
 2. The vehicle security arrangementaccording to claim 1, wherein the first code word is generated based ona keyword.
 3. The vehicle security arrangement according to claim 2,wherein the keyword is vehicle-specific.
 4. The vehicle securityarrangement according to claim 2, wherein the at least one input unitincludes a master input unit having the keyword.
 5. The vehicle securityarrangement according to claim 1, wherein the second code word isgenerated based on a keyword.
 6. The vehicle security arrangementaccording to claim 5, wherein the keyword is vehicle-specific.
 7. Thevehicle security arrangement according to claim 5, wherein the at leastone input unit includes a master input unit having the keyword.
 8. Thevehicle security arrangement according to claim 1, wherein the firstcode word is generated from a third code word provided by the theftprotection control unit.
 9. The vehicle security arrangement accordingto claim 8, wherein the third code word is randomly generated.
 10. Thevehicle security arrangement according to claim 1, wherein the secondcode word is generated from a third code word provided by the theftprotection control unit.
 11. The vehicle security arrangement accordingto claim 10, wherein the third code word is randomly generated.
 12. Avehicle security arrangement for a vehicle, comprising: a theftprotection control unit; at least one functional control unit, whereinthe at least one functional control unit is coupled to the theftprotection control unit via a bus and generates, during normal operationof the vehicle, a first code word in response to a request by the theftprotection control unit; and at least one input unit, wherein the atleast one input unit, in response to a request from the theft protectioncontrol unit, generates and transmits a second code word to the theftprotection control unit, and wherein the theft protection control unitforwards the second code word to the at least one functional controlunit via the bus if the second code word agrees with a code wordexpected by the theft protection control unit, wherein the at least onefunctional control unit compares the first code word with the secondcode word and, in the case of an agreement, the at least one functionalcontrol unit enables itself.
 13. The vehicle security arrangementaccording to claim 1, wherein the theft protection unit forwards thesecond code word to the at least one functional control unit if thesecond code word agrees with a code word expected by the theftprotection control unit.
 14. The vehicle security arrangement accordingto claim 1, wherein the first code word is generated by an authorizationalgorithm.
 15. The vehicle security arrangement according to claim 1,wherein the second code word is generated by an authorization algorithm.16. The vehicle security arrangement according to claim 1, wherein theat least one input unit includes at least one transponder.
 17. Thevehicle security arrangement according to claim 1, wherein the at leastone input unit includes at least one electronic chip card.
 18. Thevehicle security arrangement according to claim 1, wherein the at leastone input unit includes a master input unit having a keyword.
 19. Amethod for providing vehicle security by using the vehicle securityarrangement of claim 1, comprising the steps of: operating the at leastone functional control unit and the theft protection control unit in aparameterizing mode, the at least one functional control unit and thetheft protection control unit being coupled by the bus; coupling anadditional device to the bus, the additional device being adapted toinitiate a training procedure; communicating a keyword to the at leastone functional control unit and the theft protection control unit; andcommunicating the keyword from the theft protection control unit to atleast one input unit.
 20. A method for training at least one of a newinput unit and a new functional control unit in the vehicle securityarrangement of claim 1, the method comprising: communicating a keywordfrom a master input unit to the at least one of the new input unit andthe new functional control unit, wherein the at least one of the newinput unit and the new functional control unit is parameterized.